docbrown/app/controllers/concerns/api/comments_controller.rb
Anna Buianova a315bc18a6
Paginate api comments (#20304)
* Comments api pagination

* Comments api docs

* Removed Comments::Tree
2023-11-02 15:59:15 -04:00

59 lines
2.1 KiB
Ruby

module Api
module CommentsController
extend ActiveSupport::Concern
ATTRIBUTES_FOR_SERIALIZATION = %i[
id processed_html user_id ancestry deleted hidden_by_commentable_user created_at
].freeze
private_constant :ATTRIBUTES_FOR_SERIALIZATION
DEFAULT_PER_PAGE = 50
private_constant :DEFAULT_PER_PAGE
def index
commentable = params[:a_id] ? Article.find(params[:a_id]) : PodcastEpisode.find(params[:p_id])
per_page = params[:per_page] || DEFAULT_PER_PAGE
@comments = commentable.comments
.includes(user: :profile)
.select(ATTRIBUTES_FOR_SERIALIZATION)
.arrange(order: "id")
# paginating only if page is passed
if params[:page].to_i.positive?
@comments = Kaminari.paginate_array(@comments.to_a).page(params[:page]).per(per_page).to_h
end
set_surrogate_key_header commentable.record_key, Comment.table_key, edge_cache_keys(@comments)
end
def show
tree_with_root_comment = Comment.subtree_of(params[:id].to_i(26))
.includes(user: :profile)
.select(ATTRIBUTES_FOR_SERIALIZATION)
.arrange
# being only one tree we know that the root comment is the first (and only) key
@comment = tree_with_root_comment.keys.first
@comments = tree_with_root_comment[@comment]
set_surrogate_key_header Comment.table_key, edge_cache_keys(tree_with_root_comment)
end
private
# ancestry wraps a single or multiple trees of comments into a single hash,
# in the case of an article comments, the hash has multiple keys (the root comments),
# in the case of a comment and its descendants, the hash has only one key.
# Either way, we need to use recursion to extract all the comment cache keys
# collecting both the keys of each level of root comments and their descendants
# NOTE: the objects are already loaded in memory by "ancestry",
# so no additional SQL query is performed during this extraction, avoiding N+1s
def edge_cache_keys(comments_trees)
comments_trees.keys.flat_map do |comment|
Array.wrap(comment.record_key) + edge_cache_keys(comments_trees[comment])
end
end
end
end